title: Marrow cell induced osteogenesis in porous hydroxyapatite and tricalcium phosphate: a comparative histomorphometric study of ectopic bone formation.
abstract: To investigate the bone formation ability of porous hydroxyapatite (HA) and tricalcium phosphate (TCP), ceramic discs were implanted with or without rat marrow cells into subcutaneous sites in syngeneic rats. The discs of HA and TCP had identical microstructures: pore size was 190-230 microns, porosity was 50-60%, and they were fully interconnected. Implants without marrow cells (discs themselves) did not show bone formation, whereas implants with marrow cells showed bone formation in the pores of the ceramics. The bone formation of both HA and TCP occurred initially on the surface of the ceramic and progressed towards the center of the pore. The de novo bone was quantitated from decalcified serial sections of the implants. One month after implantation with marrow cells, the percentage fractions of the pore area filled with bone for implanted HA and TCP were 16.9 and 15.1, respectively. At 2 months after implantation with marrow cells, the fractions of bone were 34.3 and 30.9, respectively. These results indicate that both HA and TCP ceramics can show comparable osteogenic ability in the presence of marrow cells.
authors.affiliation: Department of Orthopedics, Nara Medical University, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Ohgushi
authors.forename: M
authors.initials: M
authors.lastname: Okumura
authors.forename: S
authors.initials: S
authors.lastname: Tamai
authors.forename: E C
authors.initials: EC
authors.lastname: Shors
authors.forename: A I
authors.initials: AI
authors.lastname: Caplan
mesh_terms: D000818:Animals; D001672:Biocompatible Materials; D001853:Bone Marrow / Q000502:physiology*; D001854:Bone Marrow Cells; D002130:Calcium Phosphates; D006882:Hydroxyapatites; D007091:Image Processing, Computer-Assisted; D008297:Male; D008856:Microscopy, Fluorescence; D016348:Osseointegration / Q000502:physiology*; D016062:Porosity; D051381:Rats; D011916:Rats, Inbred F344
chemical_list: D001672:Biocompatible Materials; D002130:Calcium Phosphates; D006882:Hydroxyapatites; C485828:alpha-tricalcium phosphate; C485830:tetracalcium phosphate; C485838:calcium phosphate, monobasic, anhydrous; C020243:calcium phosphate; C485829:calcium phosphate, dibasic, anhydrous